Ugrunaaluk kuukpikensis (oo-GREW-na-luck KOOK-pik-en-sis) is only the fourth dinosaur species unique to Alaska to be described in scientific literature. The finding was announced in a paper by the museum's earth sciences curator Pat Druckenmiller, University of Alaska Fairbanks graduate student Hirotsugu Mori and Florida State University researcher Gregory Erickson in the scholarly journal Acta Palaeontologica Polonica on Tuesday.

The name means "ancient grazer" in Inupiaq. The dinosaur had hundreds of teeth suitable for eating coarse vegetation in the polar forest that covered northern Alaska 70 million years ago and could grow as long as 25-30 feet from nose to tail, Druckenmiller said. Though the Arctic was warmer in ancient times, the creature probably lived north of the Arctic Circle year-round, enduring relatively low temperatures, "months of darkness and even snow."

But it didn't just survive, it thrived. The museum has at least 6,000 specimens from these duckbills, also called hadrosaurs, all from the Prince Creek Formation on the north side of the Brooks Range about 35 miles from the Arctic Ocean. The location was even further north when Ugrunaaluk herds grazed there, Druckenmiller said.

Though the existence of hadrosaurs in Alaska was previously known -- the first dinosaur fossils found in Alaska in 1961 were of this animal -- identifying it as a separate species with its own name took until now. Researchers compared the trove of fossils at the museum with the bones of hadrosaurs found elsewhere and spotted several differences.

Mori, who is now working in Japan, said in a press release, "The new species has a unique combination of characteristics not seen in other dinosaurs." Those include variations in the details of its skull shape when compared to Edmontosaurus, a well-known hadrosaur that lived further south.

The finding raises the likelihood that Alaska dinosaurs existed in their own environment, separate from others of their kind.

"The question has been whether dinosaurs in Alaska were the same species and migrated south with the seasons, or were they uniquely adapted to live a whole year in the Arctic," Druckenmiller told Alaska Dispatch News. "It seems like it was the latter."

One reason for that assumption is all of the species found in Alaska's far north are not found elsewhere. "So far as we know, the dinosaurs that we had living here in the Arctic were completely different species from those who lived at the same time at lower latitudes, like in Montana," Druckenmiller said. "So far, there is no overlap at all between dinosaurs in these two sites. That suggests we had our own unique polar community up here."

Researchers are now examining thin slices of bones looking for signs that, like tree rings, reveal the age of the animal and other information that may reveal physiological differences.

"If you have a whole bunch of bones -- which we do -- you can create a growth curve and find out whether they were doing the same thing as dinosaurs at lower latitudes or growing slower because of the harsh environment," Druckenmiller said. "What we're seeing right now is that they were growing just fine, thank you."

The trove of Ugrunaaluk bones comes from a concentration thought to have been created when a flood or other disaster wiped out a herd of young animals all at once. It has provided an abundance of material. "We have multiple elements of every single bone in the body," Druckenmiller said, making Ugrunaaluk the "far and away the best known dinosaur yet found in the Arctic."

The announcement comes as the Museum of the North has an exhibit focusing on dinosaurs in Alaska. A large painting of the newly identified duckbills by Anchorage artist Jamie Havens hangs just outside the exhibit. A display of three young Ugrunaaluks is currently being prepared and will be added to the exhibit later this year.